1. Field of the Invention
The field of the invention is that of probes including a set of emitting and/or receiving elements obtained by cutting from a transducer block. Such probes are currently used especially in applications such as echography. More specifically, the invention relates to unidirectional acoustic probes, including linear elements which can be excited independently of each other by virtue of an interconnection network connected to a control circuit.
2. Description of the Related Art
One method of producing these probes consists first of all in producing an assembly of a printed circuit including an interconnection network/layer of piezoelectric material/acoustic matching plates, then in cutting out the individual piezoelectric elements. International application WO 97/17145 filed by the applicant describes such a method and more particularly a method of manufacturing a probe using a printed circuit on which conducting tracks are produced, making it possible to address the various acoustic elements.
FIG. 1 actually illustrates more specifically a piezoelectric material 13 assembled to acoustic matching plates Li1 and Li2, said material being cut in two perpendicular directions by the standard sawcuts Ti and Tj. A flexible printed circuit 12 includes conducting tracks PI and vias, at least part of one and the same via being positioned on a conducting track and on a metallization Mi of associated piezoelectric material. In this configuration, linear acoustic pathways are defined parallel to the lines Tj, each acoustic pathway being subdivided into a subpathway defined parallel to the lines Ti. When the previously described assembly is produced, the probe is shaped, an operation making it possible to produce curved probes which are particularly sought in the echography field. To this end, the printed circuit including its individual acoustic elements may be adhesively bonded to the surface of a solid absorbing material having a curved surface. The flexible printed circuit is then folded over the edges of the ceramic and of the absorber as illustrated in FIG. 2. The acoustic pathways defined parallel to the axis X, are also parallel to the tracks PI, the printed circuit and conducting track assembly is, on the one hand, placed on the surface of the absorber ABS and, on the other hand, folded back vertically over the sides A and At of said absorber for reasons of compactness. In this configuration, the tracks are thus folded at 90° with a sharp angle which tends to weaken them or even break them.